Heavy Rain, has already said there won't be a sequel to that game, telling the PlayStation Blog, "We're going to be exploring a different direction, which will still be very dark and still for adults, but completely different to Heavy Rain" for Quantic Dreams' next project. That game's specifics may be a secret, but it may have a title: "Fiv5" ... yes, in the style of David Fincher's film Se7en.
Gaming trademark sleuth superannuation has turned up several clues supporting this theory, including a trademark filing with Europe's Office of Harmonization for the International Market. There's also a domain name registration by Quantic Dream, and a new hire at the developer has listed themselves as "Concept Artist: Video Game "FIVE" & "INFRAWORLD" on LinkedIn. Infraworld? Where'd we put our deerstalker hat and magnifying glass?